Unable to share twbx due to data privacy issues. Can you share an example of any video that shows this or any written material etc? One thing I believe I'm doing differently from one of the videos I've seen is that I'm using a dimension to show in the donut chart and it is converted into AGG instead of Sum as per the tutorial I was referring.Not sure if this is causing the issue.

When I do that, the value becomes highlighted in a light red color and I cant proceed further. Also, do I need to take this value up in the columns as well? I was trying to follow the directions in the video Custom Tableau Workshops - Donut Chart - YouTube but the one I end up creating is not the same.

Also, my value in the measures section is AGG and not sum, could this be causing an issue?

I tried another way, but whats happening is that when I pull the measure which is AGG, into size or angle, the whole screen freezes. Why would that be? The datatype is numeric, is there anything else which could be a problem. The tutorial I'm following is as below,